Detergent composition

ABSTRACT

A FABRIC-WASHING DETERGENT COMPOSITION INCORPORATES, AS A DTEREGENCY BUILDER, FROM 5 TO 70% BY WEIGHT OF A WATER-SOLUBLE OR WATER-DISPERSIBLE SALT OF A SUBSTANTIALLY LINEAR C10 TO C20 ALPHA-HYDOXY MONOCARBOXYLIC ACID.

United States Patent US. Cl. 252-558 9 Claims ABSTRACT OF THE DISCLOSURE A fabric-washing detergent composition incorporates, as a detergency builder, from 5 to 70% by weight of a water-soluble or water-dispersible salt of a substantially linear C to C alpha-hydroxy monocarboxylic acid.

The present invention relates to detergent compositions, and particularly to fabric-Washing detergent compositions, incorporating detergency builders.

At the present time there is considerable pressure being brought to bear on the manufacturers of detergent compositions to reduce the amount of phosphorus-containing compounds in such compositions. This situation has arisen because of the suggestion that the use of phosphorus-containing compounds in detergent compositions is a factor contributory to the phenomenon of eutrophication. Such compounds are generally present in detergent compositions as detergency builders. For many years the most commonly employed detergency builder has been sodium tripolyphosphate, and it is this compound in particular that is being blamed for the contribution of detergent compositions to the problems of eutrophication. It is common for detergent compositions to contain from 30 to 50% by weight of sodium tripolyphosphate. Sodium tripolyphosphate is a very efiicient detergency builder and can also be manufactured relatively cheaply.

Hence at the present time there is a need for a substitute for sodium tripolyphosphate that can be used to produce detergent compositions that clean elliciently and yet which will not interfere adversely with mans environment.

By the present invention it has been found that the detergency of a fabric-washing detergent composition can be built effectively if the composition incorporates a water-soluble or water-dispersible salt of a carboxylic acid having the general formula:

wherein R is a substantially straight-chain alkyl or alkenyl group containing from 8 to 18 carbon atoms. -R preferably contains from 10 to 18, and particularly preferably from 10 to 16, carbon atoms, and is preferably a straight-chain alkyl group.

Examples of suitable known carboxylic acids are 2-hydroxy-n-decanoic acid (R contains 8 carbon atoms), 2-hydroxy-n-undecanoic acid, Z-hydroxy-n-dodecanoic acid, 2-hydroxyn-tridecanoic acid, 2-hydroxy-n-tetradecanoic acid, Z-hydroxy-n pentadecanoic acid, Z-hydroxy-n-hexadecanoic acid, 2-hydroxy-n-heptadecanoic acid, Z-hydroxy-n-octadecanoic acid, 2-hydroxy-n-nonadecanoic acid, and, Z-hydroxy-n-eicosanoic acid.

3,822,222 Patented July 2, 1974 The water-soluble or water-dispersible salt is preferably an alkali-metal salt, particularly preferably a sodium salt or a potassium salt. Other cations, such as ammonium and substituted ammonium, could be used if desired.

These carboxylic acids may be prepared by alkaline hydrolysis of the corresponding alpha-bromo acids, which may be derived from the corresponding simple aliphatic carboxylic acid by various known methods, such as treatment with bromine and red phosphorus or with bromine and thionyl chloride.

The present invention provides a detergent composition comprising at least one detergent-active compound and a water-soluble or water-dispersible salt of a carboxylic acid as defined above.

These water-soluble or water-dispersible carboxylic acid salts act as detergency builders because they produce water-insoluble complexes with water-hardness metal ions, usually calcium and magnesium, and remove these ions from the wash solution by precipitation.

A detergent composition of the invention may contain more than one detergent-active compound. The total detergent-active compound content of a detergent composition of the invention will usually be from about 5 to about 35% by weight of the detergent composition, although preferably it will be from about 10 to about 25% by weight of the detergent composition. However, the detergent-active compound content of a detergent composition of the invention may be greater if desired.

One or more water-soluble or water-dispersible salts of the above defined carboxylic acids may be present in a detergent composition of the invention. Although these salts themselves possess detergent-active properties, for the purposes of this specification these salts are not being included as detergent-active compounds in a detergent composition of the invention, and therefore the total detergent-active compound content, as referred to above, does not include any water-soluble or water-dispersible salts of the above defined carboxylic acids. The watersoluble or water-dispersi-ble carboxylic acid salts may comprise from about 5 to about 70% by weight of a detergent composition of the invention, but preferably will comprise from about 15 to about 65%, and particularly preferably from about 25 to about 60%, by weight of the detergent composition. In general, the weight ratio of the total detergent-active compound content of a detergent composition of the invention to the quantity of water-soluble or water-dispersible salts of the above defined carboxylic acids present in the detergent composition can vary from about 1:10 to about 10:1, but preferably this ratio is from about 1:5 to about 5:1, and particularly preferably from about 1:5 to about 2:1.

The nature of the detergent-active compound or compounds present in a detergent composition of the invention is not a critical feature of the invention. The compound or compounds may be anionic, nonionic, amphoteric or zwitterionic in character. Examples of suitable detergent-active compounds include alkali-metal soaps incorporating fatty acids derived from natural or synthetic fats and oils, such as tallows, coconut oil, palm kernel oil, palm oil and groundnut oil; alkali-metal alkyl sulphates, such as sodium tallow alcohol sulphate; alkalimetal alkylbenzene sulphonates such as sodium dodecyl benzene sulphonate; the mixtures of anionic detergent-active compounds, known as olefin sulphonates, obtained by the sulphonation with sulphur trioxide of olefins, and the subsequent hydrolysis and neutralisation with alkaline materials; nonionic detergent-active compounds derived from the reaction of ethylene oxide and propylene oxide with reactive compounds such as alcohols, amines and amides; amine oxides; betaines; sulphobetaines; and taurine derivatives. In detergent-active compounds that are incorporated as alkali-metal salts in a detergent composition of the invention, the preferred alkali-metal is sodium. Many other examples of suitable detergent-active compounds are given in Surface Active Agents and Detergents," Vol. I (by Schwartz and Perry) and Vol. II (by Schwartz, Perry and Berch), published by Interscience Publishers in 1949 and 1958 respectively, the disclosures of which are included by reference herein.

A water-soluble or water-dispersible salt of the carboxylic acid may be used as the sole detergency builder in a detergent composition, or may be used in combination with one or more previously known detergency builders. It is particularly useful as a partial or total replacement for sodium tripolyphosphate in a conventional sodium tripolyphosphate-containing detergent composition. A detergent composition of the invention may contain from about 5 up to about 70%, preferably from about 25 to about 60%, by weight of detergency builders including one or more water-soluble or water-dispersible salts of the above defined carboxylic acids.

Other examples of previously known detergency builders that may be included in a detergent composition of the invention are trisodium orthophosphate, pentasodium pyrophosphate, sodium carbonate, sodium silicate, sodium nitrilotriacetate, sodium ethylene diamine tetraacetate, sodium carboxymethyloxysuccinate, and water-soluble or water-dispersible salts of acidic materials such as long-chain dicarboxylic acids, long-chain sulphonated carboxylic acids, citric acid, oxydiacetic acid, oxidised polysaccharides, and polycarboxylic acids. However, those detergency builders that contain phosphorus are not preferred.

In addition to the essential detergent-active compounds and detergency builders, a detergent composition of the invention can contain any of the conventional detergent composition additives in any of the amounts in which such additives are normally employed in detergent compositions. Examples of these additives include lather boosters such as alkanolamides, particularly ethanolamides derived from palm kernel fatty acids and coconut fatty acids, lather depressants, antiredeposition agents such as sodium carboxymethyl-cellulose, oxygen-releasing bleaching agents such as sodium perborate and sodium percarbonate, chlorine-releasing bleaching agents such as trichloroisocyanuric acid, inorganic salts such as sodium sulphate, and, usually present in very minor amounts, fluorescers, perfumes, enzymes, gcrmicides and pigments.

Further, a detergent composition of the invention may be produced by any of the techniques commonly employed in the manufacture of detergent compositions, such as, for instance, slurry-making and spray-drying, and the compositions of the invention may be prepared in any of the common physical forms associated with detergent compositions, such as, for instance, powders, granules, flakes, noodles, cakes, bars and liquids.

The invention is illustrated in the following Examples, in which all parts and percentages are by weight.

EXAMPLES 1 AND 2 Percent Compara- Components Ex. 1 Ex. 2 tive Ex. A

Sodium dodecyl benzene sulphonate 20 20 20 Sodium 2-hydroxy-n-dodecanoate. Sodium 2-hydroxy-n-tctradecanoat Sodium tripolyphos hate 60 Alkaline sodium sil eate, sodium carboxymethylcellulose, fluorescers, water, etc.,

Wash: 10 minutes Rinse: 2 minutes Agitation: 70 oscillations per minute Water: 25 ml. of 25 H hardness (Calcium) Temperature: 45 C.

Wash pH: 10

Cloth: liquor ratio: 1:850

The detergency was evaluated by counting the radioactivity of each disc (1 minute for each side) with a Geiger-Muller tube, before and after each washing. After correcting each count for background and paralysis time an average of both sides was taken to give corrected counts of A (before washing) and A (after washing). Detergency was then calculated from the equation;

Detergency X The following results were obtained:

Composition: Detergency (percent) Example 1 91 Example 2 94 Comparative Example A 78 These results show that the compositions of Examples 1 and 2, being compositions according to the invention, possessed detergencies superior to that of a similar composition the detergency of which was built using a conventional, phosphorus-containing detergency builder.

EXAMPLE 3 Four detergent compositions were prepared having the following essential formulations:

Percent Comparative m Compara- Ex. 3 tive Ex. D

Components Sodium dodecyl benzene sulphonate Sodium Z-hydroxy-n-hexanoate Sodium Z-hydroxy-n-oetanoate. Sodium 2-hydroxy-n-decanoate Sodium tripolyphos hate Alkaline sodium s licate, sodium carboxymethyleellulose, fluorescers, water, etc., to

The detergencies of these compositions were measured using the same standard test procedure employed in the previous Examples, except that each composition was tested at a concentration of 0.4% by weight. The following results were obtained.

Composition: Detergency (percent) Comparative Example B 14 Comparative Example C 15 Example 3 44 Comparative Example D 79 These results show that, compared to the composition of Comparative Example D built with a conventional phosphorus-containing detergency builder, the compositions of Comparative Examples B and C, containing short chain Z-hydroxy carboxylates (R is C and C in formula I), have very poor detergencies.

However, the composition of Example 3, containing a Z-hydroxy carboxylate of slightly greater chain length (R is C in formula I), has a reasonable detergency, indicating that water-soluble or water-dispersible salts of carboxylic acids corresponding to formula I in which R contains at least 8 carbon atoms are useful as detergency builders.

EXAMPLES 4 TO 6 The detergency of three detergent compositions having the following essential formulations was tested by the procedure used in Example 3, and the detergent composition of Comparative Example A was used as a Control. Two different water hardnesses (25 H calcium and 12.5 H calcium) were used. The following results were obtained:

Detergency (percent) Composition 25 H water 12.5 H water Example 6 57 93 Comparative Example A 65 83 These results show that the detergency builders of the invention compared very favourably with the detergency builder (sodium tripolyphosphate) used in the Control composition.

What is claimed is:

1. A detergent composition consisting essentially of, by 4 compound selected from the group consisting of anionic, nonionic, amphoteric and zwitterionic detergentactive compounds; and

(b) from about 5 to about of a sodium or potassium salt of a carboxylic acid havin the general formula:

R- H-COOH wherein R is a substantially linear alkyl group containing from 8 to 18 carbon atoms.

2. A detergent composition-according to claim 1, wherein R contains from 10 to 18 carbon atoms.

3. A detergent composition according to claim 2, wherein R contains from 10 to 16 carbon atoms.

4. A detergent composition according to claim 4 wherein said carboxylic acid salt comprises from about 25 to about 60% by weight of said detergent composition.

5. A detergent composition according to claim 1 wherein said detergent-active compound is an anionic detergentactive compound.

6. A detergent composition according to claim 5 wherein said detergent-active compound is an alkyl benzene sulphonate.

7. A detergent composition according to claim 1 wherein the weight ratio of said detergent-active compound to said carboxylic acid salt is from about 1:10 to about 10: 1.

8. A detergent composition according to claim 7 wherein said weight ratio is from about 1:5 to about 5:1.

9. A detergent composition according to claim 8 wherein said weight ratio is from about 1:5 to about 2:1.

References Cited UNITED STATES PATENTS 3,242,091 3/1966 Monick 25 2-109 3,305,488 2/1967 Osipow et a1 2521 17 3,449,385 6/1969 Miiller et a1 260413 3,533,954 10/1970 Davies 252- 3,770,643 11/1973 Heiba et a1 2521 17 LEON D. ROSDOL, Primary Examiner P. E. WILLIS, Assistant Examiner US. Cl. X.R. 252132, 539 

